This invention relates to the field of electrical motors and generators, and particularly to a method and apparatus for simultaneously installing a collector ring on a rotor shaft and electrically interconnecting the rotor windings to the collector ring.
The typical electric motor is comprised of a rotor shaft, a rotor having field windings, rotor end caps, and a collector ring. The rotor end caps and collector ring are aligned on the shaft such that the collector ring rotates with the rotor and so that the rotor windings are in electrical contact with the collector ring. Instead of collector rings, commutators may also be used to make connection with the rotor windings.
Prior methods of installing collector rings or commutators require separate acts to both electrically connect the ring or commutator with the rotor windings and structurally connect the rotor to the ring or commutator. Such steps increase the time, effort, and cost of installing collector rings and commutators.
Prior methods frequently require soldering or welding, which involve heat. Heating may damage components of the rotor, resulting in a high rejection rate and high costs. Furthermore, such heating may require the use of more expensive molding materials necessary to withstand the high temperatures created by these steps.
The typical method of and apparatus for installing and connecting the commutator often requires machining the ends of the rotor windings. This step also generates heat and adds to the time and cost of the installation and connection.
Collector ring and commutator installation systems require that the ends of the rotor windings be stripped of their insulating film. This step further increases the costs of installing and connecting the collector ring, introduces additional opportunities for manufacturing flaws, and reduces reliability in previous installation systems.
Previous systems also involve such components as connecting strips and materials such as solder. Elimination of these additional parts and materials from the installation/connection process would further reduce costs and increase reliability.
Previous installation and connection systems resulted in electrical connections which are exposed to the air and environment, resulting in significant and frequent damage to and failure of the electrical connections.
It is further desirable to provide a method for installing and connecting collector rings which may be easily automated in as few steps as possible.
The present invention overcomes these problems and other problems associated with existing systems and methods.